Apparatus for sterilizing flour and the like



Jan. 18, 1944. s, SMH-H 2,339,734

APPARATUS FOR STERILIZING FLOUR AND THE LIKE Filed Jan. '5, 1941 :s sheets-sheet 1 ATTORNEY Jan. 1a,v 1944. F. s., SMW'H 2,339,734

APPARATUS FOR STERILIZING FLOUR AND lTHE LIKE.

Filed Jan. 3, 1941 3 Sheets-Sheet 3 above-mentioned lnature and Patented Jain-18, 1944 APPARATUS Foa s'rnamrzlNG nova AND THE anni' Franklin'S. Smith, Bethany, Conn. Application January 3,1941, SerialNo. 372,954

` 1i claims.

A 'I his invention relates to a method and apparatuuslkfor sterilzing milled and other products in b l One of the objects of this invention is to provide an improved method and apparatus for treating products of the above-mentioned nature, particularly for thepurpose of destroying the life of insect infestation contained therein and which. may be present therein in various of its stages', such as in the form of eggs, larvae, pupae, or adults. In myco-pending applications Serial Nos. 296,543, 296,544, 321,680 and 345,715, I have disclosed various forms of apparatus suitable for destroying the life of insect infestation in products of the above-mentioned nature, such apparatus utilizing rotary product-treating units which eiect movement therethrough of the par- 'ticles of the product andof the forms of insect life under the action 'of centrifugal forces setup by the particles and the infestation, the treating units being capable of various embodiments, such as'those illustrated in the aforesaid applications, vto effect coactions which include a life-destroying mutilation of the forms of insect life. Usually the operation of these treating units is accompanied byl a discharge, with the treated product, usually peripherally and tangentially, of quanti- \ties of air, the unit acting in a. general sense somewhat like acentrifugal air pumpv or im'- peller and under various circumstances such as the character of the product being treated, the

character of the Ainstallation ofthe apparatus,v

and the like, the resultant flow of air or the resultant building up of` an air pressure at the discharge end of the apparatus is objectionable. In such apparatus, also, it is possible to have the treated product discharged peripherally and tan- 'gentially from the rotary treating unit at such velocities that its` impact with, for' example, the inner or bounding walls of the enclosing casing, effects a further breaking up of the particles 'of the product and with some products such a further milling is undesirable. One of the dominant aims of this invention is to provide an apparatus of the just described character that will in a simple, practical, inexpensive and eilicient way avoid the building up of undesirable air pressures. -Another dominant aim o f this invention -is toprovide an apparatus of the abve-mentioned nature with simple, reliable and inexpensive means for lessening d milling ofparticles of the treated* product.

Another object is to provide a method andapparatus for the' treatment of products ofthe in which control 50. the further. breaking upor of impelleddair is effected in a simple and reliable manner to avoid or minimize the above-mentionedobjectionable effect. Another object is to provide a product-treating apparatus of the above-mentioned nature with means utilizing the rotational effect of -the rotary treating unit to control the effect ofthe cui-rent of air set in motion by the rotating treating unit itself. Another object is to provide an apparatus of the kind described in the above-mentioned applications and capable of being incorporated into usual or existing mill equipmenti that will be -capable of effecting emcient-treatment ofthe product and passing the treated product on tothe next step or apparatus -in the mill equipment without carrying with the product thus passed on an objectionable or undesired volume or velocity of air ow.

Another object is to provide a simple and practical method and apparatus for treatment of products ofthe above-mentioned nature without further breaking.` up'y or milling of the product particles upon their discharge from the rotary treating unit.. Another object is tol provide an apparatus of the kirid described in the abovementioned applications with simple, practical and dependable means for preventing the product particles discharged by the rotary treating unit from being further broken up or milled.

Another object is to provide a method and apparatus for cushioning or negativing the effects.

of impacts of discharged from the rotary treatment internal casing walls.

product particles mentunit, but without further breaking them up. Another objectis in general to provide producttreating apparatus ofthe above-mentioned charimproved action, of greater eiliciency, and capable of handling a wider range of products fortreatment. Other objects will be l unit toward or against the Q. Another object is to provide simple, practical and reliable means for deecting or guiding, toward the discharge outlet of thev apparatus, product particles discharged' 'at relatively high velocity'from the -rotary treatindicatedv in the followingV 1 illustratively substantially Vshown one of the various possible of the mechanical features of Figure 1 is a with certain parts broken away and with certain other parts shown in central vertical section;

embodiments certain other parts in elevation;

Figure 3 is a horizontal sectional view of the apparatus as seen along the line 3 3 of Figure 4 is a fragmentary bottom view on a greatly enlarged scale of an air-impeller element that coacts with the treating unit Figure 5 is a sectional view as seen along the line.55 of Figure 4 Figure 6 is a plan view1on a smaller scale of a vof Figure Similar reference characters refer to similar ililarts throughout the several views in the draw` Of the various structural forms of rotary product-treating unit disclosed in my above-mentioned applications and to all of which the features of preferably relatively heavy suitably formed to a shaft I2 having a tapered which a correspondingly tapered bore of the hub n a threaded extension of the shaft I2 and constructed, as described in, for example, application Serial No. 321,680, to coact with .the carrier member II to clamp it onto the shaft or to pull it ofi' for disassembly. l

It is preferably by way of shaft I2 that the treating unit I'is supported for rotation and is driven at a suitable speed. Shaft I2 is suitably supported for rotation within a casing-like structure generally indicated by thereference character I and preferably comprising several sections, such as the lower section I6 and the upper Figure 2;

section I1 suitably secured together preferably detachably.

Upper section I1 of the products to be treated. Lower casing section I6 is provided with an outlet passage 2I iianged as at 22 to have conusually of exible mato disclarge the now sterilized 0r treated product from the apparatus and pass it on to the next machine or apparatus, such as a bagging or packaging apparatus usually forming part of the above-mentioned production or routine equipment. p Where, as in the preferred and illustrative case, it is desired to drive the treating unit I0 electrically, the shaft I2 comprise the shaft of an electric motor, such as a polyphase alternating current induction motor, of which the casing is indicated at 24 in Figure 1; the casing is provided in any suitable way with suitable bearings, such as combined radial and thrust anti-friction bearings, preferably mounted in extensions 24* and 24b of the casing 24.

In the preferred arrangement the motor frame 24 is preferably rigidly plication and for present purposes it is suflicient to` note that the motor casing 24 is rigidly secured to casing section I6 by two diametrically 7 opposed bracket structures 25, 26 adjacent the pairs of brackets 25-26 and 21 extend along diameters at say to each other and these brackets may be secured to or be formed integrally with an outer jacket or casing 30 surrounding the.motor casing 24, and with the brackets hollow or tubular the latter thus form connections to the jacket from the outside of the as an inlet for air which is drawn vinto the space between motor casing 24 and jacke* 30 by any suitable means such as an air impeller 3| accommodated in the lower portion of the jacket structure and secured to and driven by the lower end of shaft I2; tubular bracket 21 serving as outlets for the discharge of theI air which absorbs the heat losses in the motor dissipated through the conduit 32 to extend tors 33 to the motor. v

A frusto-conical member 29 is interfltted at its lower the upper end of and at its upper and inner end is intertted with-the bearing extension 24", thus forming a strong brace to tra mit to the casing structure I5 strains or thrus which the shaft I2 might exert radially.

may and preferably does The rotating parts are preferably constructed and assembled or otherwise dynamically balanced, and preferably provision is made for preventing overstressing of parts or causing unsafe vibration or other undesirable defects due to theoccurrence of any condition of unbalance arising during the operation of the treating unit.

Where the supporting and driving shaft I2 is rigidly mounted from the casing structure`I5,

secured to the floor, frame member 34 being provided with a continuous peripheral concave seat 36 in which rests a resilient or cushioning member 31 preferably of rubber and preferably in tubular form, being sufficiently thick-walled and of a quality to give the desired resiliency of action and to carry the load without permanent deformation. 'Ihe upper peripheral portion of the lower casing section I6 is provided with an outwardly directed peripheral flange 38 having a downwardly facing concave peripheral seat 40 to take the cushioningmember 31, which thus becomes interposed throughout its peripheral ex' tent between the main supporting frame 34 and the casing structure.

The product to be treated enters the apparatus through the inlet passage I8 and is fed to the entry end of the treating unit Ill into and through the spaces in which the particlesv of the product with the insect infestation pass under the'act'ion of the centrifugal forces set up in them by the rapid rotational movement given them by the rotating treating unit I: in the latter the life in the forms of insect infestation is destroyed by actions such as those described in my abovementioned applications. The sterilized product is discharged i a general tangential direction -from the peripheral or outlet ends of the spaces in the treating unit I 0, whence the product is guided by the lower frusto-conical walls of the casing section I6 to the outlet passage 2|. A typicalor illustrative speed of drive of the treating unit I0, where the latter has a diameter at the inlet openings to the spaces on the order ofand a diameter at the outlet ends of thespaces on the order of I8", is 3450 R. P. M., suitable for causing the forms of insect life to exert centrifugal forces to e'ect a life-destroying mutilation lthereof in coaction with the surfaces of the spaces formed 'in the-treating Aunit I0. But as earlier above noted, the treating unit I0 can set up a movement of air through its space or spaces and act like an air impeller, apparently operating upon particles or molecules of air much in the same general way as it operates upon particles of the product to effect 150W or movement therethrough. Thus, the treating unit I0 can be effective to set up in the casing structure I5. a pressure or head of air which effects a movement of air through the outlet passage 2| in an amount or at a rate greater than the normal air enf trained by the product itself and, depending upon various factors,such as the character of the apparatus connected to the conduit 23; this excessive air 'iiow is undesirable or\objectionable.

In such case, I provide for lessening or avoiding such undesirable effects. Where the treatment unit is constructed to have a lower car- An illustrative rier element like the member I I, extending from its periphery to the shaft I2, the member II, though rotating, forms In effect an unbroken barrier between an upper portion or zone of the interior of the casing and alower portion or zone, the elements of the treating unit III, supported by or related to the upper face of the member II, being in effect in this vupper zone and the inlet passage I8 feeding the product to v the elements of the. treating unit I0 may comprise a plurality of frusta-conical elements 42 suitably held in spaced relation to form lspaces 43 therebetween of a thickness 0n the order of 11s". .In much .the same way'that/the prod uct particles are passed through the spaces 43 by the centrifugal forces set up in them, air is I0 a substantial portion of the'air discharged into the lower zone by the Impeller action of the treating unit. This I achieve preferably by several coacting features of construction and action.

Illustratively, I provide at the under side of the carrier element II, that is, the side exposed toward the lower zone, means for taking up air from the lower zone and discharging it into the upper zone and preferably directly into the inlet ends of the spaces 43 of the treating unit. Such a means may be embodied directly into the carrier member II and in the .drawings it is illustratively so shown. Thus, wherel the member II is made of substantial thickness, say on the order of l/j, I provide a series of aper' tures 45 arranged preferably ina circle of a diameter on the order of the diameter of the treatment unit I 0 at the inlet openings to the spaces 43 thereof. Illustratively, these apertures may be illustratively eight in number and the under face of the carrier member II at the leading side of each aperture 45'is shaped as by milling to form with the thereby exposed and trailing wall of the aperture a bucket-like recess generally indicated by the .reference character 46 and better shown on enlarged scale in Figures 4 and -5, in both of which the arrow indicates the direction of rotation of -ther carrier member II.

Thus, each aperture 45 may be formed as by milling and in Figures 4 and 5 is indicated at 4'I the above-mentioned milled-out or cut away portion of the member I I. 'I'he cut away-portion will be seen to be of gradually increasing `depth and of gradually diminishing width in the the air-impelling capacity of the treating unit f i itself. Preferably, and illustratively, this ratio also to effect appropriate distribution of infed product particles to the various treatment spaces. In construction, it comprises a plurality of upstanding elements illustratively eight in number, and shaped as is better shown in Figure 3, being uniformly spaced about a circle and having their lower faces shaped to fall in a frustoconical plane to mate with and rest against a corresponding frusto-conical band-like portion of the upper surface of the carrier member and in which band-like portion the apertures 45 terminate, as is better shown in Figure 2. Thereby, the member 50 may be coaxially alined with the carrier member to which it may be secured as byscrews 53 (Figures l and 2) passing through the member and threaded respectively into the members 5|.

At their upper ends Athe members 5| are joined together by an inner annular portion 52 (Figure 2), the latter being threaded as shown. Elements 5| and 52 are preferably integrally formed. v

The outer vertical faces of the members 5| fall in a cylinder of a diameter equal to the smaller diameter of the frusto-conical plate-like members 42 of the treating unit, whereby the latter are concentrically alined with each other and with the carrier member being held in spaced relation from each other and from the carrier member by uniformly distributed rib-like elements 54, illustratively four for each of these members, ,formed in or secured to the upper faces thereof and angularly arranged on each, as is better shown in Figure 3. Thus, four such rib elements 54 may be provided on the carrier member I and upon each member 42, and as the latter are assembled to the carrier member as by slipping them over the member 50, the rib elements 54 of the various members are brought into vertical alinement, as appears better in Figures 2 and 3. Over the uppermost of the member 42 and resting upon the ribs 54 thereof is a frusto-conical clamping member 55 of suitably heavy construction for clamping, in a, preferred mannerlater described, the stacked, spaced members 42 between itself and the carrier member I. With such a construction, also, the members 42 may be made of sheet metal and in such case they are preferably flared out or given a curved flange at their peripheries, as indicated at 42a in Figure 1, thereby to stiffen each member 42 to hold it in its frusto-conical shape.

Extending vertically in the'outer face of each member 5| is a V-shaped groove or channel 56 .of substantial cross-section, a cross-section related to the direction of-rotation of the treating unit in the manner indicated in Figure 3.where the unit is to rotate in counterclockwise direction. The lower portion of the channel 56 overlies an air discharge aperture 45 and the members 5|, each with a channel 56, correspond in number to the number of apertures 45 s ol that the air impelled through the latter is guided upwardly by the channels 55. Laterally or outwardly, however, the channels 56 are open and face corresponding circumferential portions of the annular entry ends of the treatment spaces 43, thus to permit the direct discharge of air from the channels 56 into the treatment spaces. Such discharge is, moreover, aided by the suction-like effect produced in the treatment spaces themselves and also by the angularity of the walls of the V-shaped channels 56 (see Figure 3) relative to the direction of rotation. With air thus forced from the lower zone and fed into the inlet ends of the treatment spaces, thus for virtually continuous recirculation, a substantial portion of the air-impelling capacity of the treating unit is utilized in taking part in such recirculation, the remainder being suitable to handle the air entrained with the product that enters the apparatus through the inlet passage I8.

As is better shown in Figure 3, the spacing between the vertical elements 5| form passages 51 connecting the annular space about the central hub portion of the carrier member and to which space incoming product isdischarged for distribution among the treatment spaces 43, to

the latter, and it is through the passages 51 that the product tobe treated with its entrained air passes into the treatment spaces.

'Ihe product particles dropping downwardly through the inlet passage I8 are set into rotary movement-by the frusto-conical hub-like central portions of the carrier member and, aided by the peripheral velocities of points on the surfaces of the latter, increasing with the radius, exert centrifugal forces which cause them to move into the entry or inlet ends of the treatment spaces 43, accompanied by Whatever forms of insect life may be in the product. The vertical elements 5I, moving in counterclockwise direction, as viewed in .Figure 3, move at substantial peripheral velocities, and the inner edge portions of the leading faces 5|a thereof in effect pick up or catch up, in rapid succession, from the abovementioned outwardly moving product in the torous-shaped space about the hub-like central portions of the carrier member relatively small quantities or increments of' the infested product, and though there may be a non-uniform distribution, more or less, of the product in the torous-shaped space, the equally spaced elements 5|, by an action like that just described, eiect'a substantially uniform distribution of moving flour particles and insect infestation into and throughoutv the entry ends of the treatment spaces 43, as are exposed to the passages 5l, and eiect also a regulating or limiting action upon the quantity of product supplied to the treatment spaces. These impeller-like actions upon the particles of the product maybe aided by a similar impeller action upon air entrained in or with the product entering theapparatus through the inlet passage I8.

The trailing faces 5|b of the elements 5| slant at an angle, as indicated in Figure 3, away from the direction of rotation, and at such an angularity that particles of the product will not adhere to or pack onto these surfaces. The inner faces of the members 5| are preferably broken into two surfaces, such as a cylindrical surface 5| of relatively small peripheral extent and coaxial with the axis of the member 50, thus to the member 50, and a surface 5| which may be arcuate but wmensiants away from the directon of rotation appropriately so that particles ofy the product will not adhere to or pack up onto it.

The annulus 50 which, as above -described, serves in this form of construction to axially alineethe elements or members 42 of the treating unit, preferably also serves to -carry suitable means to press the clampingv member 55 against the stacked elements I2 and toward the carrier member Ii, and such means preferably comprises a ring member 58 of U-shaped cross-section, as shown in Figures 1 and 2, its outer annuwrench, may be turned to effect a tight securing of the members 42 and the upper or clamping member 55, to` the carrier member I I, the outer under part of the ring member 58 and the upper end part of the clamping member 55- being suitably'shaped to provide mating seats through which the clamping pressure of the ring member 58 is transmitted to the clamping member 55` and thus a secure clamping of the stacked members 42, with the rib members 5l (Figures 2 and3) in vertical alinement between the members 55 and li,iseiected. l e With the particles ,of the product and the forms of insect infestation entering the treatment spaces 43, they are,moved, due to the centrifugal forces they ex'ert, against the under slanting away from the direction of rotation, in eect strikes the form of insect life or the latter is impacted against it, with a force also effectingl a life-destroying mutilation,.. crushing or deformation. The face of such a rib may also act as a surface along which, in an outward direction,

the form of insect life is pressed and as the latter progresses Valong it, for ultimate discharge from the treating unit, is moved lwith avmutilat'- ing, crushing, or deforming action, resulting from the rubbing or abfading of the form of insect life as'it moves therealong, thus also eiectv ing destruction of its life.

Discharging from the treating unit, the sterilized product is guided by the inclined, preferably frusto-conical, walls of the lower casing section I6 to the outlet passage 2| through which v it passes on, for example, to a bagging or packaging means, but in vview of the continued circulation of a certain quantity of air, preferably on the order of 80% of the air impelling capacity of the treating unit, eected as above described, only the desired and relatively small quantity of air passes out of the apparatus with the treatedproduct. These and the above de- 4 scribed actions'arepreferably aided by a guide faces of the members l2 and 55, the movement being outwardly and downwardly in expanding curvilinear paths about the axis of rotation of the treating unit. Should any particle of product, insect infestation, or the like, detach itself f for some reason from the material progressing along any such surface, the juxtaposed surface ofA the treatment space, rotating as part of the unit, catches such detached particles or otherwise sets them into motion at high velocity,

thus to cause them to exert a sufficient centrifugal force to move them outwardly and again against'the surfacefrom which the detachmentl has taken place. The parts are dimensioned and 'the speed of drive selected so that the movement communicated to the forms of insectinfestation along any of therabove-mentioned under surfaces, in a curved path of increasing'radius, is

- minmimu and maximum diameters on the order or 10" and 1sf', respeetive1y,tne speed of drive may be on the order of 3450 R. P. M., 'to effectv dependable life-destroying action.- Y

The product particl and the forms of insect infestation now devoid of life, due to the rubbing, abrading or crushing action, discharge peripherally in a tangential direction .from the outlet ends of the treatment spaces 43. Should a form of insect life, in its curvilinearypath of movement not be discharged from a treatment space before it encounters a rib element ll (see Figure 3), the leading face of the rib element,

` and partition generally indicated by the reference character 60 (see Figure l) and preferably in the form of a sleeve of circular cross-section, being arranged preferably coaxially with the vertical axisof the apparatus. This sleeve-like guide 60 has an intermediate generally cylindrical portion 60a of a diameter about the same as the outside di eter of the rotary treating unit lll and it has-an upper portion 60h, substantially frusto-conical, fitting rather closely underneath the carrier member 'I l and termihating with its upper peripheral edge forming. a mouth 60 just about encompassing the circularly arranged air impeller buckets '4S-41; it has a lower portion 60 substantially frustoconical, the included angle being preferably equal to the included angle ofthe frusto-conical casing section l6terminating at its lower edge 4 in a mouth 608 of substantial diameter and, as shown in Figure 1, spaced substantially above the discharge passage 2|. I

The guide member 66 may be constructed in sections (not shown) to facilitate assembly and,

fastening to the` pairs of supporting brackets 25F26 and 21, and, with the smaller-dimensioned motor and housing structure with'in it, thus formsan annular channelv or passageway for movement of air upwardly. tothe impeller buckets 46-41.

Adjacent the lower end-of the apparatus, they substantial amount of product with it, particularly where the product particles vare fine, as with products ylike ilour. At or in the region 'adjacent the lower mouth ill, therefore, separation of the particlesfrom the recirculating air stream takes place, the particles dropping or passing out of the apparatus through the disn charge passage 2i and the portion of the air being recirculated passing upwardly through the mouth 60S, whence it is guided to the intake apertures 45 or to the impeller buckets 46-41 and thus fed to the inlet ends of the v treatment spaces. This separating action is probably aided also by the reversal of direction of air ow as the air enters the mouth 60B, the` inertia of the particles resisting such change in direction of movement As above noted, there are some products whose particles are in eifect sized and a further breaking up of which is undesirable; such particles, discharged tangentially from the peripheral discharge or outlet openings in the treating unit i and hence at points of maximum radius 'and of maximum peripheral velocities, might be broken up by striking the inside wall of the upper portion of the lower casing section I6, probably aided in their flight by the relatively high velocity of air discharged by the treating unit. Such undesirable effects I prefer to counteract or avoid in the following manner:

The upper thick walled portion 38 (Figure l) of the casing section I6 I provide with a rabbet 62 (see also Figure 10) in which is seated, as by a push fit, an annular diaphragm member 63 which is preferably of tapered cross-section, terminating with arelatively sharp inner edge about and suitably spaced for clearance from the outer edge of the clamping member 55. Diaphragm member 63 thus in effect coacts with the clamp*- ing member 55, the clamping ring 58 and the downwardly projecting portion` of the inlet flange I9.to block oi, between them and in eiect the upper casing section I1, an uppermost zone or space in the apparatus. This zone will be seen to be'in effect annular and to it, at portions of lesser radius, I arrange to feed or supply air. This I maydo by providing for the passage to it of some of the air that is recirculated, as above described.

For example; I may provide passages leading to-,this blocked oil.' zone from the channels 5B in the upright members i and into which air is impelled by the bucket-like elements 46-41, and for this purpose the clamping ring 58 is provided with a suitable number of vertical apertures or passages 64 (Figure 3) suitably distributed about a circle of thesame diameter as the circle about which the channels 58 are distributed; these passages 64 preferably incline away from the direction of rotation, as indicated in Figure 3, sorthat discharge of air therefrom is aided by the rotary motion and 'at their lower ends they communicate during the operation of the apparatus air .may

be fed or supplied to the inner part of the blocked oil' zone. Some of that air passes inwardly toward the inner ange I9, being forced or drawn through the small clearance gap between the latter and the adjacent edge of the clamping ring 5l, thus preventing egress therethrough of untreated product or of forms oi' insect life. The inner face of the ring Il is preferably inclined at a suitable angle. as indicated in Figures 1 and 2,

so 'that product particles like flour cannot adhere to it or become deposited thereon.

The major portion of such air, however, moves downwardly andoutwardly. To eifect this latter movement, the upper face of the rotating member 55, being of increasing radius, may take part. but preferably the member 55 is provided with an air impeller element which may take the form of an annular plate-like member 66 preferably of tapering cross-section, as shown in Figures 1 and 2; member 66 may be secured to the member 55 in any suitable way, as by welding, and it is channeled or apertured as at 61, adjacent its connection to the member 55, to permit air moving in the space between the member 55 and a frustopeller element 66: this space, being of increasing radius and with the velocity of air now therethrough increasing, is preferabiy of diminishing cross-section in thedirection of air flow, as indicated in Figures 1 and 2.

Impeller element B6 extends about'one-third or one-half of the radial extent of the annular space between the diaphragm member 63 and the parallel or horizontal portion i1 of the upper casing section I1, being in a vertical sense equidistantly spaced from the two faces of these parts.

Impeller element 66, acting through its upper and lower faces, as viewed in Figures 1 and 2, impels or discharges the air tangentially, at relatively high velocity, into the annular space which acts asa diffusion chamber, in effect converting the velocity energy of the discharged air to apressure head effective to ow the air in a general downward direction through passages 'i0 in the diaphragm member 63 and distributed about the latter adjacent the upper end of the inside wall of the casing section i6.

These passages 'i0 in the diaphragm member 63 may be formed, for example, as shown inFigure 6, where the member 63 is cut or milled at intervals as at 'iiis about its periphery, giving it al toothed-like eiect, or the apertures may be otherwise formed, as by broaching, as indicated at 10b in Figure 8. Preferably, and as shown in Figures 'I and 9, the end walls of the apertures are inclined downwardly and opposed to the direction of rotation ofthe treating unit, thus giving the streams of air, which pass downwardly through the passages 10, a directional eiect or component which, when considered in a view like that of Figure 3, is clockwise where the direction of rotation of the treating unit is counter-clockwise.

Where the member 63 is constructed as in Fig- A.ure 6, the outer or endv parts of the toothed-like members intervening the slots 10* rest in the rabbet 62 (see also Figure 10) which is deep enough also to take a downwardly extending circular rib or ilange i 1c of the upper casing section i1 which,

` with the conduit ange I9, is thus centered with the rest of the apparatus. Assembly of the parts may be insured as by threaded studs 'Il projecting upwardly from the casing part 3l and accommodated in slots or apertures in the peripheral iiange portion of the upper casing section i1 to etlect clamping of the latter as by nuts 12. Where the member 63 is constructed as in Figure 8, the peripheral marginal portion rests in the rabbet' 62 and the rib |1 takes over it. In either case. the passages 10, as is better shown in Figure 1, are thus preferably positioned close to the wall of the casing section It and being relatively numerous and uniformly distributed about the circumler-U charged tangentially at high velocity from the treating unit leaves the latter in a path which,

if continued, would lead it into impact with the wall' of the casing structure. As it continues along its path, ail'ected somewhat by gravityY as to direction, giving it a movement along a twisted curve having helical and spiral components, the

particle meets the downwardly and in a sense helically moving curtain of air formed by the streams coming .down through the passages 10, the helical vcomponent being in a Idirection opposite that of the helical component of movement of the particle. 'I'he particle is thus slowed up in its movement; if it gets through the curtain-like air stream and strikes the upper partof the casing section I6, it does so with so little kinetic energy that it is not further broken up, while, on the other hand, it may have its energy of motion so dissipated or its direction of movement so changed that it simply passes downwardly in the annular space between the casing section I6 and the guard member 60 for discharge through the discharge passage 2|.

The air impelling action of element 66 may thus also aid in the recirculating action in which impeller buckets 46-41 take part.

With the rotary treating unit rigidly mounted, as by the -brackets 25, 26 and 21, or secured to the casing structure I 6, precession, in the event that an unbalance occurs in the treating unit, may take placeV by the action of the resilient member 31 which forms a resilient connection between the vcasing structure and the supporting frame 34, the resilient connection falling in a plane which is at or slightly above the center of gravity of the rotating parts. When unbalance takes place, the yieldability of the resilient member 31 permits such a shifting of the apparatus a as corresponds to a precessional motion, the resilient mounting permitting the rotating members and the load to assume, as a center of a tty-A ration, the center of gravity of the rotating mass and its load. The resilient member opposes and ultimately negatives the forces .that bring about the precessional motion and thus undue vibration or straining of the parts is avoided. By this p referred mounting the diaphragm member 63, the lower end of the inlet flange I 9 and the guide member 6D partake of the precessional motionof the rotating mass and thus the clearances between the just-stated parts and their immediately coacting or adjacent rotating elements, such as the clamping member 55, the clamping ring 58, and the portion 60h of the guide 60, respectively, may be made relatively small and the various coactions between these parts made more efficient.

Thus, it will be seen that there has been provided inv this invention a method and apparatus in which the various objects above noted, together with many thoroughly practical advantages are successfully achieved. It will be seen that undesirable effects of an air-impelling action of the treating unit are dependably overcome and while, for illustrative purposes,v I have abovementioned that the fraction of the air-impelling air capacity of the treating unit to be recirculated is on the order of 80%, it will be understood that,

by suitably proportioning various of the air-im- 'pelling parts, any. desirable ratio may be achieved. It will alsobe seen that,where desired, breaking up of l particles of the product to be treated is dependably avoided.

As many possible embodiments may be made of themechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or

shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense..

I claim:

. 1. An apparatus for destroying life of the inparticles of the product with forms of insect infestation in a direction from said inlet means to.

said outlet means, there being intervening said inlet and said outlet means, means for destroying the insect lift in the product, said rotary means having the characteristic'of impelling airv from said inlet means for discharge through said outlet means, said rotary means comprising a plurality of superimposed spaced elements 0f which the lowermost is a carrier member having means forming passages for the movement of air from the -under side of the carrier member to said inlet means, and means rotatable with said carrier member-for impelling air into-said passages and to said inlet means.

2. In apparatus of the character described, in combination, a rotatable material-treating unit 'comprising a carrier member having means for rotatably supporting it, said carrier member supporting a plurality of annular plate-like members having means holding them in spaced relat tion to form treatment spaces therebetween which are peripherally open at the smaller diameter thereof to form inlet means and peripherally open at the larger diameter thereof to form outlet means, a plurality of members in spaced relation about the mst-mentioned peripheries of.

said members and forming means for distributing infed particles of, material to said inlet means, said members having channels exposed to .said inlet means and said carrier member having passages therethrough respectively in communication with said channels in said members,v and means carried by said carrier member and effective, upon rotation, to impel air through said passages and into said channels for entry into said inlet means.

3. Iny apparatus for effecting the destruction of all insect life in a owablelproduct composed of individual solid parts, tliefcombination of, a rotary treating device having a treating surface against which the product and insect life engages during the treatment, means forming an inlet having a substantially unrestricted passageway to allow a substantially even stream of l said product to iiow freelyto said rotary treating device, means to feed said product to said inlet so that-itmay now through said treating device,

means to rotate said treating device at a high speed to provide a life destroying engagement between every individual particle of said insect life and said treating surface during passage of said product through said treating device, means forming a product outlet extending substantial- -ly around said treating device through which the product. falls away from said treating device, and means for interposing in thepath of the .product particles as they leavesaid treating deof said treating device.

6. In apparatus for effecting the destruction Aof all insect life in a owable product composed of individual solid parts. the combination of, product directing means to receive the product and to directthe product along a path which extends to a treatment area through which the product flows freely, rotary treating means effective within said treatment zone to contact each particle of insect life within the product to impart lethal trauma to all of said insect life, means forming a casing surrounding said treating means and spaced therefrom to provide an annular channel into which the product is discharged subsequent to treatment by the rotary treating means, and means for directing a iiow of air into said channel and at an angle to the direction/of ow of the product to lessen the velocity of the solid parts of the product thereby to prevent disintegration thereof upon impact with the casing.

7. Apparatus as claimed in claim 6, in which 'said last-mentioned means comprises an air im'- peller fastened to and accordingly rotatable with said rotary treating device.

8. Apparatus as claimed in claim 6, in which said last-mentioned means includes a rotatable air impeller and means forming a driving connection between said rotary treating device and impeller, whereby said impeller is rotated upon rotation of the rotary treating device.l

9. In apparatus for eiecting the destruction of all insect life in a flowable product composed of individual solid parts, the combination of, product directing means to receive the product and to direct the product along a path which extends to a treatment zone through which the product flows freely, rotary treating means eiective within said treatment zone to contact `each particle of insect life within the product to impart lethal trauma to all of said insect life, .means forming a casing surrounding said treating'means, they Walls o'f said casing being spaced from theldis-"fl charge end of said rotary treating device to form an annular space into which the product is discharged by said treating device, means for inf troducing into said space a stream of air to diminish the velocity of the solid parts of the product as they leave the treating device, means forming a product outlet through which the product 1s discharged subsequent to treatment, and means for recirculating said air from a point adjacent said outlet to a point adjacent said product directing means.

10. In apparatus of the character described in combination, a material-treating unit comprising a rotatably supported carrier plate, an annular plate member mounted upon said plate and axially spaced therefrom, the central opening in said plate member forming an entrance for the material to be treated, and a plurality of hollow memberscircumfrentially spaced about the inner edge of said plate member and spanning the space between said plate member and said plate, said hollow members being connected to holes in said plate and constructed to provide passage'v ways from the outside of the carrier plate to f the outside of the plate member.

11. Apparatus as claimed in claim 10 in which there is a casing surrounding said material-feed- 'ing unit and spaced therefrom together with means for directing air along said casing from one side of the treating unit to the other.

FRANmlm S. SMITH. 

